· Chromite ore processing residue (COPR) is a waste derived from the chromate extraction from roasted ores and is deposited in some countries in landfills. The objective of this study was to investigate the leaching characteristics of hexavalent Cr [Cr(VI)] from two COPR samples obtained from unlined landfills in the Kanpur area of northern India.READ MORE
A process for obtaining chromium enriched chromite from chromite ores comprising the steps of: dry chlorinating the ores at a temperature between 400 °C and 750 °C to produce a chlorinated substrate containing acid soluble ferric oxide, acid soluble ferric chloride and acid insoluble chromium enriched chromite; digesting the chlorinated substrate with hydrochloric acid to dissolve the ferric ...READ MORE
· The production process of chromite sand. Chromite ore is predominantly used in the production of ferrochrome – an alloy of chrome and iron containing between 50% and 70% chromium. The production of steel is the largest consumer of ferrochrome, especially stainless steel production which contains between 10% and 20% ferrochrome content.READ MORE
The sulfuric acid leaching kinetics of South African chromite was investigated. The negative influence of a solid product layer constituted of a silicon-rich phase and chromium-rich sulfate was eliminated by crushing the chromite and by selecting proper leaching conditions. The dimensionless change in specific surface area and the conversion rate of the chromite were observed to exhibit a ...READ MORE
IntroductionA huge amount of chromite overburden containing 0.4% to 0.9% nickel and 0.02% to 0.05% cobalt is generated in the process of chromite ore mining in the Sukinda mines of Orissa, India. The ore belt spreading over a stretch of 7 km in length from Kansa in the east to Muruabil in the west  is known to be the only nickeliferous ...READ MORE
Chromite ore processing residue (COPR), derived from the so-called high lime processing of chromite ore, contains high levels of Cr(III) and Cr(VI) and has a pH between 11 and 12. Ferrous sulfate, which is used for remediation of Cr(VI) contamination in wastewater and soils via reduction to Cr(III) and subsequent precipitation of iron(III)/chromium(III) hydroxide, has also been proposed for ...READ MORE
· The sulfuric acid leaching kinetics of South African chromite was investigated. The negative influence of a solid product layer constituted of a silicon-rich phase and chromium-rich sulfate was eliminated by crushing the chromite and by selecting proper leaching conditions. The dimensionless change in specific surface area and the conversion rate of the chromite were …READ MORE
· The average grade of the metallurgical chromite ore was 43.4 pct Cr2O3, with 52 pct of the ore having a chromium-to-iron ratio of 3:1 or over, 17.6 pct having a ratio between 2:1 and 3:1, and 30.4 pct having a ratio less than 2:1. Chemical-grade chromite ore generally ranged from 40 to 46 pct Cr2O3 with a chromium-to-iron ratio of 1.5:1 to 2:1.READ MORE
leaching of Cu from the chalcopyrite, which would otherwise not leach at temperatures below 50°C . This process is followed by heap reclamation, a water wash step and re-stacking of the heap onto a new pad for a high temperature cyanide leach, achieved via solar heating of solution, to extract precious metals (Pt, Pd and Au) (Eksteen et al ...READ MORE
· In the process of carbonate leaching, the chromium‐containing residue after magnesium extraction can be used as iron ore or raw material in the cement industry . In addition, aluminum in chromite ore can be extracted and recovered in the green process as aluminum hydroxide [Al(OH) 3]. Thus, the comprehensive use of all valuable elements (Cr ...READ MORE
leaching indicates super-saturation of the solution and precipitation of the products. INTRODUCTION The working lining of copper refining (anodic) furnace made of magnesia-chromite (MCr) refractory materials is exposed to high temperatures and aggressive slags. The fire refining process of copper is …READ MORE
The extraction of chromate from chromite via the sulfuric acid leaching process has strong potential for practical use because it is a simple and environmentally friendly process. This paper aims to study the sulfuric acid leaching process using chromite as a raw material via either microwave irradiation or in the presence of an oxidizing agent. The results show that the main phases in ...READ MORE
· The process is called leaching. Indeed, as every morning billions of people unwittingly use this extraction technique to enjoy the organoleptic properties of tea and coffee, at the same time many industries greatly benefit from the vast number of leaching applications. For example, leaching is widely used in the biological and food processing ...READ MORE
· Leaching is widely used in the biological and food processing industries, such as the separation of sugar from sugar beets with hot water. The extraction of oils from peanuts, soybeans, sunflower seeds, cotton seeds, and halibut livers. In pharmaceutical industry, many products are obtained by leaching plant roots, leaves, and stems. In the ...READ MORE
· acid treatment process: (i) the chromium in the chromite is difﬁcult to leach because of the high stability of the chromite spinel in sulfuric acid solution at room temperature and atmospheric pressure; (ii) iron, magnesium, and aluminum ions can be released into the leachate concomitantly as chromium is leached, and the removal of impurities isREAD MORE
ground and roasted chromite ores. In the roasting process, insoluble trivalent chromium [Cr(III)] present in the ores oxidizes to soluble hexavalent Cr [Cr(VI)], which is then recovered by aqueous leaching for further processing (Burke et al., 1991). The technology dates back to 1845 and is still inREAD MORE
· In nature, the commonly occurring reactive metal oxides of titanium, chromium, aluminium, and vanadium often chemically combine with the transition metal oxides such as iron oxides and form complex minerals. Physico-chemical separation of transition metal oxides from the remaining reactive metal oxides is th 2015 most accessed Green Chemistry articles Elemental Recovery and …READ MORE
· This study reports on the leaching characteristics of COPR from the soda ash roasting process that contained 8,500 mg/kg of Cr(VI), indicating poor recovery during the leaching process. To this end, leaching with different extraction solutions was studied as a function of time. The DI water, 0.1M NaOH and 1M NaOH leaching results were similar ...READ MORE
MODELLING CHROMUM LEACHING FROM CHROMITE ORE PROCESSING WASTE YALÇIN, Sezgin M.S., Department of Environmental Engineering Supervisor: Prof. Dr. Kahraman Ünlü September 2003, 92 pages Chromium has been widely used in many industrial applications. As a result of chromiteREAD MORE
Developing treatment and disposal strategies and health-based clean-up standards for chromium containing wastes continues to be an important environmental regulatory issue because of …READ MORE
· As a result of chromite ore processing, large amounts of chromite ore processing residue (COPR) material that can be classified as hazardous have been produced and released into the environment. Therefore, knowledge of migration behavior and leaching rates of chromium through waste materials are of primary concern for environmentally sound ...READ MORE
· The large increase in leaching of Cr(VI) upon infiltration of sulfate, either as FeSO4 or Na2SO4, was caused by anion exchange of sulfate for chromate in the layered double hydroxide mineral hydrocalumite, a process for which scanning electron microscopy with energy-dispersive X-ray microanalysis provided direct evidence.READ MORE
· The plant will test a proprietary chloride-based process (flowsheet), pioneered in Canada, for the recovery of TiO2, V2O5 and Fe2O3 from run-of-mine ore at a feedrate of 10 kg/d. It will test the operation of each of the major unit operations of the flowsheet on a continuous basis: leaching of the mineralized material, TiO2 precipitation, iron ...READ MORE
The leaching of Cr for chromite tailings can be explained by two main processes. The first main process for Cr leaching is associated with the presence of phosphate anions in solution, which can exchange with chromate and bi-chromate anions, promoting the presence of Cr (VI) [ 46] in solution.READ MORE
· In summary, the following kinetic equation can be applied to describe the pressure leaching process for chromite ore in 50 wt% KOH solution: (3) 1 - ( 1 - x) 1 / 3 = 20537 × ( P O 2) 1.16 × e - 64020 RT × t. The reaction activity of KOH solution decreases significantly with the decrease of KOH concentration, while the oxygen solubility and ...READ MORE
leaching processleaching process for chromite in lebanon. We are a professional mining machinery manufacturer, the main equipment including: jaw crusher, cone crusher and other sandstone equipment;Ball mill, flotation machine, concentrator and other beneficiation equipment; Powder Grinding Plant, rotary dryer, briquette machine, mining ...READ MORE
leaching processleaching process for chromite acid treatment process (i) the chromium in the chromite is difcult to leach because of the high stability of the chromite spinel in sulfuric acid solution at room temperature and atmospheric pressure (ii) iron magnesium and aluminum ions can be released into the leachate concomitantly as chromium is ...READ MORE
· Leaching Process. Leaching Process:-Leaching is a mass transfer operation in which we have a solid material which either contains components which are valuable to us or components which are considered an impurity of the solid, no matter what the case, such components are called solute.We take a liquid which is called a solvent and contact it intimately with the solid in order to …READ MORE
· This study presents chemical, mineralogical, and leaching characterization of chromite ore processing residue (COPR) derived from the soda ash process, which is currently replacing the lime-based process in China, the world''s largest chromite processor.READ MORE
from the calcium roasting process is the residue of water leaching after mixing chromite, sodium carbonate (Na 2 CO 3), and dolomite and calcining at high temperatures.15 This residue contains a large amount of calcium and a small amount of iron, aluminum, chromium, etc. However, the COPR from the non-calcium-roasting process always contains a ...READ MORE
The leaching process of chromite ore is a typical LO reaction, and the oxygen mass transfer in the KOH sub-molten salt solution is a vital factor. In order to intensify the reaction, the catalytic effect of potassium nitrate was examined in previous studies . It was found that the introduction of …READ MORE
· The leaching kinetics study indicated that the leaching process of chromium was controlled by the surface chemical reaction between the chromite ore processing residue and sulfuric acid. Overall, the direct acidic leaching process could not achieve high leaching efficiency and resulting in a large amount of impurities which was hard to separate ...READ MORE
The leaching behavior of chromite by sulfuric acid in the presence of oxidant was studied experimentally in this work, where most tests were carried out at 160 °C.The results indicated that magnesium and aluminum were leached out together from the silicate phase and porous amorphous silica was produced as a product layer, while the spinel phase gradually shrank with the duration of leaching.READ MORE
Chromite is a crystalline mineral composed primarily of iron(II) oxide and chromium(III) oxide compounds. It can be represented by the chemical formula of FeCr 2 O 4 is an oxide mineral belonging to the spinel group.The element magnesium can substitute for iron in variable amounts as it forms a solid solution with magnesiochromite (MgCr 2 O 4). A substitution of the element aluminium can ...READ MORE
AMC is a specialized company that develops, designs, manufactures and sells large-scale mining machinery and equipment such as cone crushers, jaw crushers, impact crushers, sand making machines, sand washing machines, and feeding and screening machinery.
Group"s overseas wholly-owned investment company-China AMC Cameroon Mining Company
The company has a modern, high-standard garden-style production park. The heavy-duty industrial production workshop contains various large-scale CNC machining centers, cold work centers, assembly centers, electric hydraulic centers, spraying centers, and storage guarantee centers.
The company has a complete product quality system and standardized production management system. All products are designed, produced, assembled and inspected in accordance with international quality system standards, and have successfully passed ISO9001 quality management system, ISO14001 environmental management system and ISO45001 occupational health management system certification .
A successful foreign trade company needs not only good talents and organizations, but also good supplier support.
Offer advanced and reasonable complete solutions for aggregates & ore processing.
China AMC Cameroon Company Sarl (hereinafter referred to as CMCC) has obtained the right to exploit a granite mine with reserves of 33 million tons in the Leboudi II area of Yaoundé. AMC's design team conducted in-depth discussions and exchanges with the engineer team for many times. Through unremitting efforts, various difficulties were finally overcome, and the production line installation, commissioning and operation were completed on schedule, according to quality, quantity, and zero accidents. To ensure that CMCC produces and sells stone materials as scheduled, with an annual output and sales of 8 million tons, it is the largest stone plant in Yaoundé and even Cameroon.contact us
At the end of 2020, Dongguan Feiwei Construction Engineering Co., Ltd. plans to establish a high-quality tuff sand and gravel aggregate production line in the Hefei-Zongyang section of the Dezhou-Shangrao Expressway. After many discussions, the AMC design team rushed to the site to design a complete set for the customer. Production line, while guaranteeing to provide the best customer service before, during and after sale.contact us
Société Transatlantique Cameroun Sarl (hereinafter as Transatlantique) is mainly engaged in the production and sales of various building stones. In the akak1 area of Yaounde, the capital of Cameroon, Transatlantique has obtained the mining right of a granite mine with reserves of about 12 million tons, producing and selling 1 million tons of stone annually. Through careful calculation and construction, AMC design team overcame all kinds of tests, and finally completed the installation, commissioning and operation of the production line on schedule, And the project meet the requirement of quality, quantity and zero accident.contact us
We sincerely welcome you to contact us through the hotline and other instant messaging methods. Whether it's project consultation or feedback, we will serve you in the fastest way and spare no effort to save time for customers.
AMC is committed to providing customers with a complete set of quarry and mining development solutions to meet the specific needs of various aspects and bring sustainable profitability to your sand and gravel and other businesses.
If the services you need are not listed above, please contact us through online consultation, we will respond to you as soon as possible.